Unwrap the mozzarella sticks and freeze for at least 30 minutes.
In a shallow bowl, whisk eggs and milk together.
In a second bowl, combine breadcrumbs, crushed cornflakes, garlic powder, salt, and pepper.
Dip each mozzarella stick into the egg mixture, then into the breadcrumb mixture, pressing gently to coat. Repeat to double coat.
Place the coated sticks on a tray and freeze again for at least 1 hour.
Heat vegetable oil in a deep pot to 350°F (175°C).
Fry the cheese sticks in batches for about 1-2 minutes until golden and crispy.
Drain on paper towels and serve hot with marinara sauce.